Concentration of phenolic compounds in aqueous mate (Ilex paraguariensis A. St. Hil) extract through nanofiltration

In order to establish the parameters to obtain aqueous mate extract with the highest content of total phenolic compounds (TPC), the response surface methodology (RSM) was used. The extract obtained at 100 °C, within 3 min and with pH of 6.0 was submitted to nanofiltration to concentrate the phenolic compounds of mate (Ilex paraguariensis A. St. Hill). The total phenolic content values in the permeate and in the concentrate collected in different volumetric reduction factors (VRF) were different from those detected in the feed extract. The concentration of phenolic compounds increased when VRF was increased, reaching the highest retention index (R) of 0.99 when VRF was 4.0. The permeate and the concentrate obtained in VRF 4.0 were verified through HPLC. 4,5-dicaffeoylquinic acid and gallic acid showed retention index of 1.00 and 0.95, respectively, while 3,4-dihydroxybenzoic acid and chlorogenic acid reached 0.99 and 0.98, respectively.     

Familiarity and lexicality as determinants of the generation effect.

Two experiments addressed the question of whether representation in the mental lexicon is a sufficient condition for obtaining the generation effect. Contrary to an earlier report (Nairne, Pusen, & Widner, 1985), our experiments showed that low-frequency words did produce significant retention advantages when generated, but only when items were rated as highly familiar to the subjects; when low-frequency words were recognized as words but were rated low in familiarity, no generation effect emerged. Overall, our results support the position that lexical representation is neither a necessary nor a sufficient condition to produce the generation advantage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Counting backwards produces systematic errors.

59 undergraduates rapidly counting backwards made 2 types of systematic errors. They missed repeated digits (e.g., 77) and decade numbers (e.g., 80). The percentage of repeated-digit errors increased and the percentage of decade-number errors decreased when S said only the digits comprising a given number (e.g., "three-four" instead of "thirty-four"). This pattern of errors is explained in terms of the short-term memory processes involved in counting. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhancing effects of similarity on long-term memory for order.

Four incidental learning experiments examined the effects of stimulus similarity on long-term memory for order. Although most current theories of order retention easily handle, and often predict, a disruption in order retention under conditions of high intralist similarity, the opposite result, an enhancing effect of similarity, presents a significant interpretive puzzle. All 4 of the present experiments demonstrate conditions in which phonological or categorical similarity significantly improves both absolute and relative long-term memory for sequential order. Tentative interpretations of these results are provided, on the basis of list discrimination arguments and the operation of study–phase reminding processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)